Laminated fuel line and connector

ABSTRACT

A laminated fuel line has an inner layer of a synthetic material such as Nylon, an intermediate vapor barrier layer that contains a polyethylene terephathalate material (such as MYLAR), and an outer layer preferably of a high temperature resistant thermoplastic material such as a polyamide or VICHEM olefinic/PVC. A channeled fuel tube has an inner fuel jacket concentrically formed within and spaced from a relatively larger outer jacket, each of which can be formed with the laminated structure above. A connector for the channeled fuel line has a tubular end connecting element for connecting between the inner and outer fuel lines, a tubular inner connecting element for connecting to the inner line through the end connecting element, and a tubular outer connecting element connecting over both the end connecting element and the inner connecting element. The outer connecting element has a first passageway for communicating with the inner line and a second passageway for communicating with the outer line. The first and second passageways are formed perpendicular to each other.

FIELD 6F THE INVENTION

The present invention relates to a laminated fuel line and a connectortherefor.

BACKGROUND

Laminated fuel lines usable with fuels containing alcohol (known asgasohol) are described, for example, in U.S. Pat. Nos. 5,167,259;5,076,329; 5,038,833 all issued to Brunnhofer. Such laminated fuel linestypically employ a petroleum resistant material such as polyamide, i.e.,Nylon 6, Nylon 66, Nylon 11 or Nylon 12.

When a gasohol or alcohol containing fuel is used, in particular, thealcohol component, as well as other fuel components thereof, can diffuseinto the polyamide layer causing it to swell. Basically, liquid fuelcomponents can displace plasticizer contained within polyamide resins,creating communication paths for the fuel components to permeate to theexterior of the fuel tube. This problem can be avoided by using metalfuel lines, but metal lines are subject to corrosion and are moredifficult to use. In U.S. Pat. No. 4,758,455 issued to Campbell et al.,a composite fuel and vapor tube uses an inner liner of a petroleumresistant material such as nylon and a metal strip surrounding andadhered to the outer surface of the liner, and a flexible outer jacketof a halogenated plastic or elastomer. This tube is bendable to anunsupported self sustaining shape and has good heat dissipationproperties. Notwithstanding the advantages obtained therefrom, the costof manufacturing such a construction is relatively expensive.

U.S. Pat. No. 5,076,329 to Brunnhofer contemplates using a barrier layerformed of a copolymer of ethylene and vinyl alcohol with a relativelythicker polyamide layer formed over the inner polyamide layer inattempting to prevent or reduce the alcohol component from permeatingthrough its outer polyamide layer, which can swell the line. Brunnhoferdescribes that. a barrier layer of polyvinyl-alcohol alone is noteffective against alcohol. It requires a relatively thick polyamideouter layer in contact with the barrier layer. Specifically, althoughthe inner polyamide layer can undergo swelling, the relatively thickerouter layer that is not directly exposed to the fuel resists theswelling force. Although the polyvinyl barrier may offer some degree ofprotection against alcohol permeation when properly laminated or bondedto the outer layer, its effectiveness diminishes when the barrier layerbecomes delaminated therefrom. U.S. Pat. No. 5,219,003 issued toKerschbaumer discloses that the adhesion between polyamide and polyvinylis very slight such that they can delaminate easily. Corrosivechemicals, such salts, which can develop from copper or metal ionspresent in the fuel, can penetrate between the layers through the fuelends and delaminate the barrier layer, reducing the vapor barriereffectiveness.

In addition, due to the extreme brittle nature of the polyethylene vinylalcohol barrier layer, it cannot withstand cold impact tests. In thisregard, Kerschbaumer contemplates use of three different polyamidelayers, with the barrier layer formed of nylon 66 in attempting form alaminated fuel tube capable of withstanding cold impact tests.

The present invention provides a low cost fuel tube that alleviates thedeficiencies of the prior art.

SUMMARY OF THE INVENTION

The present invention is directed to a laminated fuel line, a laminatedchanneled fuel line, and a connector for the channeled fuel line. Thelaminated fuel line comprises a tubular inner layer of a petroleumresistant thermoplastic material having a central bore forming an innerfluid passageway, a vapor barrier layer concentrically formed around incontact with the inner layer, and an outer layer of a thermoplasticmaterial concentrically formed around the barrier layer. The barrierlayer is preferably composed of aluminum coated polyethyleneterephthalate film (MYLAR), but can be composed of any one or acombination of MYLAR, a metal coated MYLAR, MYLAR polyvinyl fluoride(PVF) and MYLAR polyvinyl difluoride (PVDF) films. The inner and outerlayers can be composed of a polyamide such as Nylon 12. However, if thefuel line is exposed to a high temperature environment, it is preferablefor the outer layer to be composed of heat resistant thermoplastic,preferably an olefinic/PVC alloy material sold under the trade nameVICHEM.

Another aspect of the present invention is a channeled fuel linecomprising a tubular inner tubular layer or jacket, an outer jacket of asubstantially larger size formed over the inner jacket, and means formaintaining the inner jacket spaced from the outer jacket. The innerjacket can be formed of a single layer of a petroleum resistantthermoplastic material having a central bore forming an inner passagewayfor fluid communication or can be formed of the aforementioned laminatedfuel line.

The space formed between an inner side of the outer jacket and outerside of the inner jacket defines a separate outer fluid communicationpassageway. The outer jacket includes aforementioned vapor barrier layerof a MYLAR film to block fuel components from permeating therethrough.Specifically, the outer jacket comprises a first or intermediary layerand a second or outer layer of a petroleum resistant material, with thebarrier layer sandwiched therebetween.

The spacing means can be a plurality of radially extending spacersformed between the outer jacket and the inner jacket to maintain theinner jacket concentric with the outer layer. The outer passageway isdefined between the outer side of the inner jacket, the inner side ofthe outer jacket and the sidewalls of the spacers.

Preferably, the inner jacket and the first and second layers of theouter jacket are formed of a polyamide such as Nylon 6, Nylon 66, Nylon11 or Nylon 12. Again, if the fuel line is to be used in areas of highheat, then it is preferable for the outer or second layer of the outerjacket to be formed of aforementioned VICHEM olefinic/PVC material.

In the channeled fuel line, although the radially extending spacers canbe separately formed, it is preferable for them to be integrally formedwith the inner side of the outer jacket or with the outer side of theinner jacket.

Another aspect of the invention is a connector for the above describedchanneled type of fuel line having inner and outer fluid passageways.The connector comprises a tubular end connecting element, a tubularinner connecting element and a tubular outer connecting element. Theouter connecting element connects to the outer passageway to communicatetherewith whereas the inner connecting element connects to the innerpassageway through the end connecting element. The inner connectingelement is positioned substantially coaxially with the end connectingelement. The outer connecting element connects both the end connectingelement and the inner connecting element. The outer connecting elementhas a first passageway for communicating with the inner passageway and asecond passageway for communicating with the outer passageway. The firstand second passageways are substantially perpendicular to each other.

Specifically, the end connecting element comprises a tubular proximalportion having at least one side wall opening that can communicate withthe second passageway and a distal portion formed by a plurality ofcircularly spaced tubes extending substantially collinearly with theproximal portion. The distal portion is dimensioned to frictionallyengage between the inner and the outer jackets.

The inner connecting element comprises a tubular distal portiondimensioned to sealingly engage an inner wall of the inner jacket and aflange at a proximal end thereof for abutting and sealing the proximalend of the end connecting element.

The outer connecting element comprises a distal portion and a tubularproximal portion. The distal portion has an inner chamber dimensioned topermit insertion of the proximal portion of the end connecting elementalong with the flange. The distal portion of the outer connectingelement sealingly engages over the outer jacket, with the distal portionconcentric with the inner connecting element and the end connectingelement. The first passageway is formed within the proximal portion ofthe outer connecting element and is substantially collinear with theinner connecting element, whereas the second passageway extendssubstantially perpendicular from the distal portion of the outerconnecting element.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other features, aspects, and advantages of the presentinvention will become much more apparent from the following description,appended claims, and accompanying drawings.

FIG. 1 shows a cross-section of a fuel line according to the presentinvention.

FIG. 2 shows a cross-section of a channeled line according to thepresent invention;

FIG. 3 shows a cross-sectional view of the channeled line connectorshown with its connecting element assembled.

FIG. 4 shows an exploded cross-sectional view of the connecting elementsof the connector.

FIG. 5 shows a front view of the end connecting element taken along line5--5 of FIG. 6.

FIG. 6 shows a cross sectional view of an alternative embodiment of theouter connecting element.

DETAILED DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a cross section of a single laminated fuel tube 10according to the present invention. The laminated fuel line comprises atubular inner layer 12 of a petroleum resistant material having acentral bore forming an inner passageway 11 for fluid, a vapor barrierlayer 14 concentrically formed over and in contact with the inner layer,and an outer layer 16 of a thermoplastic material concentrically formedover and in contact with the barrier layer. The barrier layer ispreferably composed of commercially available aluminum coatedpolyethylene terephthalate film (MYLAR), but can be composed of any oneor a combination of commercially available MYLAR, aluminum coated MYLAR,MYLAR polyvinyl fluoride (PVF) and MYLAR polyvinyl difluoride (PVDF)films. The aluminum coating is a relatively thin coating formed on bothsides or on either side thereof. The aluminum is preferably thin so asto not effect the MYLAR layer's bending or flexing properties. Although,the aluminum coating is thin, it enhances the permeation barriereffectiveness.

Unlike prior art barrier layers, the present MYLAR composition barrierlayer need not adhere to the walls of the inner and outer layers to beeffective. Rather, according to the present invention, the MYLARcomposition barrier layer is merely sandwiched in place by preferablyshrink fitting the outer layer tightly over the MYLAR barrier layer by aconventional means or extrusion method.

The inner and outer layers can be composed of polyamide, including Nylon6, Nylon 11, Nylon 12 and Nylon 66, with Nylon 12 being preferred, andvariation of these Nylons in conductive grades. Conductive Nylons arepreferable in that they resist any potential electrostatic discharge(ESD) that can occur in some applications. If the fuel line is exposedto a high temperature environment, it is preferable to form the outerlayer with a high temperature resistant thermoplastic. One commerciallyavailable material is an olefinic/PVC material sold under the tradenameVICHEM.

FIG. 2 shows a channeled fuel line 100 according to the presentinvention. The channeled fuel line comprises an inner fuel layer orjacket 110, a substantially larger outer jacket 120 and spacing meansfor maintaining the outer jacket 120 concentric with the inner jacket110. The inner jacket has a central bore forming an inner passageway 112for fluid communication. Although the inner jacket is shown as a singlelayer, it can also have a laminated structure similar to the fuel linedescribed above with respect to FIG. 1. The outer jacket comprises abarrier layer 124 sandwiched between an intermediary or first layer 122and an outer or second layer 126. Again, the barrier layer 124 ispreferably composed of any one or combination of the aforementionedaluminum coated MYLAR, MYLAR, MYLAR PVF and MYLAR PVDF films, sandwichedin the manner described above with respect to FIG. 1.

The spacing means is defined by a plurality of radially extendingspacers 130 formed between the inner and outer jackets. The spacers 130can extend substantially the entire length of the channeled fuel line tomaintain the outer jacket 120 concentric with the inner jacket 110.Preferably, the spacers 130 are spaced apart at the same intervalsaround the inner jacket. Although the spacers can be formed throughoutthe length of the fuel line, they can also be placed at intervals alongthe length of the fuel line if desired, as long as the spacers maintainthe outer jacket concentrically spaced within the inner jacket.Moreover, although the radially extending spacers 130 can be separatelyformed, it is preferable for them to be integrally formed with the firstlayer 122 as shown in FIG. 2 or integrally formed with the inner jacket110 for ease of assembly, where the outer jacket can be slid over,extruded, or formed over the inner jacket. The space formed between theouter jacket and the inner jacket forms an outer fluid passageway 132.

The inner jacket 110 and the first layer 122 of the outer jacket 120directly exposed to the fuel can be composed of any suitable petroleumresistant material such as a polyamide, i.e., Nylon 6, Nylon 11, Nylon12 and Nylon 66. The outer layer 126 of the outer jacket 120 can also beany suitable thermoplastic layer, such as Nylon 12. However, if the fuelline is exposed to a high temperature environment, such as an enginecompartment, it is preferable to form the outer layer with theaforementioned heat resistant VICHEM olefinic/PVC material.

The inner passageway 112 can be used, for example, as a fuel feed lineand the outer passageway 132 as a fuel return or vapor return line, orvice-versa. In this regard, since the inner jacket 110 is shielded bythe outer jacket 120, including the barrier layer 124, any fuelcomponent permeating through the inner layer is prevented from reachingthe environment. Any fuel component permeated through the inner jacketis returned or captured through the outer passageway 132. Accordingly,the inner jacket does not need a separate barrier layer. However, theinner jacket 110 can be formed of the a laminated structure similar tothe aforedescribed fuel line 10 shown in FIG. 1 if desired, such as whentwo different fuels are conveyed through inner and outer passageways.

The present channeled fuel tube can serve as a dual fuel path. However,if the outer passageway is used for conveying fuel, fuel componentpermeating into the environment will be greater due to the fuel beingdirectly in contact against the inner wall of the outer jacket 120.Accordingly, the lowest permeation can be achieved by conveying fuelthrough the inner passageway 112 and recovering any permeated vaporthrough the outer passageway 132.

FIGS. 3-6 show a connector 200 for a channeled type of fuel line 100having an inner fuel passageway 112 and an outer fuel passageway 132.The connector comprises a tubular end connecting element 220, a tubularinner connecting element 240 and a tubular outer connecting element 260,260'. The end connecting element 220 connects to the channeled fuel line100, between the outer side of the inner jacket 110 and the inner wallof the outer jacket 120. The inner connecting element 240 connects tothe inner side of the inner jacket 110 through the end connectingelement 220 and is positioned substantially coaxially with the endconnecting element 220. The outer connecting element 260, 260' connectsboth the end connecting element 220 and the inner connecting element 240and is positioned coaxially over both the elements 220 and 240. Theouter connecting element 260, 260' has a first connector passageway 270for communicating with the inner passageway 112 and a second connectorpassageway 280 for communicating with the outer passageway 132. Thefirst and second passageways 270 and 280 are substantially perpendicularto each other.

Specifically, the end connecting element 220 comprises a tubularproximal portion 222 having at least one side wall opening 224 forcommunicating with the second passageway 280 and a distal portion 226formed by a plurality of circularly spaced tubular arms 228 extendingsubstantially collinearly with the proximal portion. Each of the arms228 has a passageway 229 communicating with the second passageway 280via the passageway 223 defined by the inner wall of the proximalportion. The arms 228 are dimensioned to frictionally engage between theinner side of the outer jacket 120 and the outer side of the innerjacket 110. The proximal end 225 of the end connecting elementpreferably includes an annular chamfer 221.

The inner connecting element 240 comprises a tubular member having adistal portion 242 dimensioned to sealingly engage the inner side of theinner jacket 110, and a flange 244 formed at a proximal end thereof. Thedistal portion 242 can have tapered outer friction enhancing ridges 243to ensure a tight, sealing connection with the inner jacket. The flangehas an annular groove 246 for seating a seal, such as an O-ring 250. Thedistal portion 242 is inserted through the passageway 223 from theproximal end 225 toward the distal end 227 of the end connecting element220 until the flange 244 and the O-ring 250 sealingly abut the proximalend 225 of the end connecting element. In this respect, the chamfer 221is provided to accommodate insertion of the proximal end 225 between theouter periphery of the O-ring and the wall of the chamber 263. TheO-ring can be made of any conventional material useable with nylon orfuel line quick connect fittings for conventional gasoline fuel systems,such as fluorosilicone (FVMQ), FVMQ/fluorocarbon (FKM) blend, andperfluorovinyl terpolymer fluorocarbon (FKM-GFLT). Although thepreferred embodiment is shown with an O-ring 250, the connectoraccording to the present invention can also be made without using suchan O-ring.

The outer connecting element 260, 260' comprises a distal portion 262and a proximal portion 264. The distal portion 262 has a chamber 263defined by the wall thereof which is dimensioned to permit insertion ofthe proximal portion 222 of the end connecting element along with theflange. The distal portion 262 sealingly engages the outer side of theouter jacket 120 and is concentric with the inner and end connectingelements. The flange 244 is positioned to abut against a radial wall265, as shown in FIG. 3. The chamber 263 has a first segment 263adimensioned to sealingly engage the proximal portion 222 of the endconnecting element 220 and a second segment 263b having a largerdimension to permit insertion of the end portion of the outer jacket 120as shown in FIG. 3. The second passageway 280 that is perpendicular tothe passageway 263 is defined by a tubular connector 282, 282' extendingsubstantially radially from the distal portion 262, which communicateswith the chamber 263. Again, the tubular connector 282 can have taperedouter ridges 283 on the outer surface thereof to enhance friction. Inthe alternative embodiment, as shown in FIG. 6, the tubular connector282' can be structurally similar to the proximal portion 264.

The first passageway 270 is defined by an inner wall of the distalportion 264 and is substantially co-linear with the chamber 263, theinner connecting element 240 and the end connecting element 220. Theradial wall 265 has an opening for permitting fluid communicationbetween the chamber 263 with the first passageway 270.

In assembly, the arms 228 of the end connecting element 220 is pushedinto the outer passageway 132 until the end of the fuel line abutsagainst the larger proximal portion 222. The distal portion 242 of theinner connection element 220 is inserted through the passageway 223 andpushed into the inner passageway 112 until the flange 244 abuts againstthe proximal end 225 of the end connecting element. The end of the fuelline connected to the end connection element 220 and the innerconnection element 240 is inserted into the distal portion 262 of theouter connecting element 260, until the proximal portion 222 of the endconnecting element occupies the chamber portion 263a and the flange 244of the inner connection element abuts against the wall 265, with theopening 224 aligned with the second passageway 280. The end of the fuelline is further pushed into the distal portion 262 until the outerjacket 120 abuts against the first segment 263a. The flange 244sealingly abuts against the wall 265 so that the inner passageway 112communicates with the first passageway 270 via the inner connectingelement 240. The outer passageway communicates with the secondpassageway 280 through the passageways 229, the passageway 223 and theopening 224. Accordingly, the fluid communication between the inner andouter passageways 112 and 132 are kept separate.

Given the disclosure of the present invention, one versed in the artwould readily appreciate the fact that there can be other embodimentsand modifications that are well within the scope and spirit of thedisclosure set forth herein, but not specifically depicted anddescribed. Accordingly, all expedient modifications readily attainableby one versed in the art from the disclosure set forth herein that arewithin the scope and spirit of the present invention are to be includedas further embodiments of the present invention. The scope of thepresent invention accordingly is to be defined as set forth in theappended claims.

What is claimed is:
 1. A fuel line comprising:a tubular inner layer of apetroleum resistant material having a central bore forming an innerpassageway for fluid; a vapor barrier layer comprising at least one of ametal coated polyethylene terephthalate polyvinyl fluoride or a metalcoated polyethylene terephthalate polyvinyl difluoride concentricallyformed around said inner layer; and an outer layer concentrically formedaround said barrier layer, wherein said barrier layer minimizespermeation of fuel components to said outer layer to minimize escape offuel components into the environment.
 2. A fuel line according to claim1, wherein said barrier layer is composed of aluminum coatedpolyethylene terephthalate.
 3. A fuel line according to claim 1, whereinsaid petroleum resistant material is a polyamide.
 4. A fuel lineaccording to claim 1, wherein said outer layer is composed of athermoplastic material.
 5. A fuel line according to claim 4, whereinsaid thermoplastic material of said outer layer is polyamide or anolefinic polyvinyl chloride material.
 6. A fuel line according to claim1, further comprising an intermediate layer concentrically formedbetween said inner and outer layers, said intermediate layer having aplurality of elongated channels defined by an outer side of said innerlayer and inner sides of said intermediate layer, forming a discreteouter fluid communication passageway.
 7. A fuel line according to claim6, wherein said intermediary layer includes a plurality of radiallyextending spacers to maintain said intermediary layer concentricallyspaced away from said inner layer.
 8. A fuel line comprising:a tubularinner layer of a petroleum resistant material defining a firstpassageway for fluid communication; an outer jacket of a substantiallylarger size positioned about said inner layer; and means for maintainingsaid inner layer.spaced from said outer jacket, wherein the spacebetween said outer jacket and said inner layer defines an outer fluidcommunication passageway, wherein said radially extending spacers areintegrally formed with said inner layer; and a vapor barrier layersurrounding said fluid passageways to block fuel components frompermeating therethrough.
 9. A fuel line according to claim 8, whereinsaid inner layer, intermediary layer and said outer layer are composedof polyamide.
 10. A channeled fuel line comprising:a tubular inner layerof a petroleum resistant material defining a first passageway for fluidcommunication; an outer jacket of a substantially larger size positionedabout said inner layer; means for maintaining said inner layer spacedfrom said outer jacket, wherein the space between said outer jacket andsaid inner layer defines an outer fluid communication passageway; and avapor barrier layer comprising at least one of a metal coatedpolyethylene terephthalate polyvinyl fluoride or a metal coatedpolyethylene terephthalate polyvinyl difluoride surrounding said fluidpassageways to block fuel components from permeating therethrough.
 11. Achanneled fuel line according to claim 10, wherein said barrier layer iscomposed of aluminum coated polyethylene terephathalate.
 12. A channeledfuel line according to claim 10, wherein said petroleum resistantmaterial is a polyamide.
 13. A channeled fuel line according to claim10, wherein said outer jacket comprises a first layer of a petroleumresistant material and a second layer, wherein said barrier layer issandwiched between said first and second layers.
 14. A channeled fuelline according to claim 13, wherein said second layer is formed of apolyamide or an olefinic polyvinyl chloride-material.
 15. A channeledfuel line according to claim 13, wherein said means for maintaining saidouter jacket spaced from said inner jacket comprises a plurality ofradially extending spacers formed integrally with said first layer. 16.A multi-channeled fuel line comprising:a tubular inner liner of apetroleum resistant material having inner and outer circumferentialsurfaces with the inner surface defining a first passageway for fluidmovement therethrough; an outer jacket concentrically positioned aroundthe outer surface of the inner liner, the outer jacket having outer andinner circumferential surfaces; means for maintaining the inner linerspaced from the outer jacket to define a second passageway between theouter surface of inner liner and the inner surface of the outer jacketfor fluid movement therethrough, wherein said means for maintaining saidouter jacket spaced from said inner jacket comprises a plurality ofradially extending spacers formed integrally with said first layer; anda vapor barrier layer positioned adjacent to the inner surface of theouter jacket to prevent fluids in the first and second passageways frompermeating through the outer jacket, said vapor barrier comprising atleast one of a metal coated polyethylene terephthalate, polyethyleneterephthalate polyvinyl fluoride or polyethylene terephthalate polyvinyldifluoride.
 17. A channeled fuel line according to claim 16, whereinsaid barrier layer is composed of aluminum coated polyethyleneterephthalate.
 18. A channeled fuel line according to claim 16, whereinsaid petroleum resistant material is a polyamide.
 19. A channeled fuelline according to claim 16, wherein said outer jacket comprises a firstlayer of a petroleum resistant material and a second layer, wherein saidbarrier layer is sandwiched between said first and second layers.
 20. Achanneled fuel line according to claim 19, wherein said second layer isformed of a polyamide, a conductive polyamide or an olefinic polyvinylchloride material.